TKS fluid dripping from inspection panel after flight

[redbaron1982]

I'm exercising my TKS to get it back in normal operation conditions. 

Today after a two hours flight, in which I ran the system for 45 minutes right after take off, when I put the airplane back in the hangar I notice that there was tks fluid dripping from an inspection panel on the left wing.

I removed the inspection panel fwd of the one dripping and checked the TKS manifold and it was all dried and doesn't seem to be any leak. 

Is it possible that while in flight the fluid can get inside inspection panels and after landing some of them drip?

Or should I start looking for a leak in the system?

 

 

[Ragsf15e]

1 hour ago, redbaron1982 said:

I'm exercising my TKS to get it back in normal operation conditions. 

Today after a two hours flight, in which I ran the system for 45 minutes right after take off, when I put the airplane back in the hangar I notice that there was tks fluid dripping from an inspection panel on the left wing.

I removed the inspection panel fwd of the one dripping and checked the TKS manifold and it was all dried and doesn't seem to be any leak. 

Is it possible that while in flight the fluid can get inside inspection panels and after landing some of them drip?

Or should I start looking for a leak in the system?

 

 

It makes a mess, but running it on the ground to see all the panels wet is relatively normal.  You could probably take a look in that inspection panel after to see if fluid is entering from somewhere?

[Fly Boomer]

5 hours ago, redbaron1982 said:

Is it possible that while in flight the fluid can get inside inspection panels and after landing some of them drip?

It gets into the tail when used in flight, but have not heard of the fluid going into the wing via inspection cover.  Certainly possible, but there would have to be a substantial air path into the wing to carry the fluid with it.

[GeeBee]

IMHO as long as you have good flow out of all protected surfaces I would not worry. 

[exM20K]

I don’t think there should be fluid getting inside the wing.  It is pretty straightforward to look at the supply tubes nd proportioning valve to find any leak.  A leak won’t get better, and if a connection parts, the system won’t pressurize.

-dan

[redbaron1982]

38 minutes ago, GeeBee said:

IMHO as long as you have good flow out of all protected surfaces I would not worry. 

It does seem to have good flow out of all surfaces, at least in flight both wings were wet.

 

7 minutes ago, exM20K said:

I don’t think there should be fluid getting inside the wing.  It is pretty straightforward to look at the supply tubes nd proportioning valve to find any leak.  A leak won’t get better, and if a connection parts, the system won’t pressurize.

-dan

I did remove the inspection panel that gives me access to the proportioning valve in that wing and it was all dried, no leaks there.

[Danb]

I recently had a leak with fluid running out of the belly. It as a fitting on one of the nylon lines, which I had to replace. I’d take a good look fluid goes where it wants sometimes all over the place.

[exM20K]

1 hour ago, redbaron1982 said:

I did remove the inspection panel that gives me access to the proportioning valve in that wing and it was all dried, no leaks there.

Ok, well it’s coming from somewhere, and if it were my plane, I’d want the inside of the wing dry of TKS fluid. It can take some searching.  
 

I was getting a mist of fluid in the avionics bay.  It was not obvious where it was coming from.  Rejected hypotheses included the fuselage gap at the wing root with flaps extended, accumulating leaks in the belly, a bad vent in the tank, and others.  Finding that mechanism of mess was not easy. It turns out that a sagging fill tube had created a trap between the filler and tank, and in flight, the low pressure in the avionics bay was sucking the fluid back up ro the vented cap. Problem solved with a few PMS zip ties to straighten the run to the tank.

My factory installation did not leave much at all in the way of service loops in the lines; some were nearly taut.  That tension can help pull stuff loose.

good luck.

-dan

[GeeBee]

If it really bothers you, run your system on the ground, open the panel, if the back is dry, not to worry, if it is wet, trace the puddle. 

[Fritz1]

Best way to check wetting of panels is running on ground and observe drip pattern on asphalt, 

Take inspection panel out, dry inside, run 5 min on ground, check for fluid, if none put panel back in, fly, run system for 5 min, land, take panel out and check for fluid inside

 

[redbaron1982]

Kind of a side question, I looked at removing the panel that drips, and I found that some screw heads are stripped. Also the screws are painted over and it looks as if it was not removed in a long time. Are these panels supposed to be removed during annual?

The dripping (very small) is coming from here:

 

 

[Fritz1]

Looks like fluid might seep in at one panel in front and go out the other behind, would not be too worried about it, these panels are hardly ever removed, extract screws and/or drill out pop rivets when convenient

[redbaron1982]

If these panels are hardly removed, how do they inspect for corrosion during annual inspections? These panels are between the main wing spar and the aft stub spar.

[Ragsf15e]

9 hours ago, redbaron1982 said:

If these panels are hardly removed, how do they inspect for corrosion during annual inspections? These panels are between the main wing spar and the aft stub spar.

Having just done my annual, I can tell you that the first thing I do is remove every inspection panel on the airplane so my IA can look in. That being said, sometimes he tells me I can skip one or two where he can see the area from the one next to it.

[LANCECASPER]

On 3/11/2024 at 7:50 PM, redbaron1982 said:

Kind of a side question, I looked at removing the panel that drips, and I found that some screw heads are stripped. Also the screws are painted over and it looks as if it was not removed in a long time. Are these panels supposed to be removed during annual?

The dripping (very small) is coming from here:

One of the first things I do when I buy an airplane is buy new stainless screws for the inspection panels. On some of the old screws (with paint on) the heads strip out easily and have to be removed with an ez-out. After the first annual I have all new screws so taking off the inspection panels for the next annual goes much easier. In years after that, if a screw head looks questionable I never put it back in - it'll look worse by the time I get it out the next year.

Also I never "remove" the panel for the annual. I leave one screw on the end of the panel and loosen it so I can pivot it out of the way for the inspection. No lost panels during the annual. 

[redbaron1982]

I ran the system today while on the ground and I didn't see any dripping from the inspection panel. 

I have a theory, is it possible that the TKS fluid is getting into the wing through the speed brakes? And then from there run towards the lowest part of the wing (which is close to the inspection panel that was dripping)?

Any thoughts or has someone seen this?